Dispersant viscosity modifiers with sulfonate functionality

ABSTRACT

A lubricating composition includes an oil of lubricating viscosity and an oil-soluble dispersant viscosity modifier, which includes an olefin-based polymer backbone and at least one pendent functional group. Each of the at least one pendent functional group is independently attached to the olefin-based polymer backbone by a linking group. The at least one pendent functional group includes a sulfonate moiety.

This application claims the priority of International ApplicationPCT/US2015/050166, filed Sep. 15, 2015, and claims the benefit of U.S.Provisional Application Ser. No. 62/050,317, filed Sep. 15, 2014, fromwhich the PCT application claims priority, the disclosures of each ofwhich are incorporated herein by reference in their entireties.

BACKGROUND

Aspects of the exemplary embodiment relate to a dispersant viscositymodifier, and more specifically to a sulfonated dispersant viscositymodifier and to a lubricating composition, such as an engine oil, whichincludes the described dispersant viscosity modifier. Aspects of theexemplary embodiment also relate to a method for use of the describeddispersant viscosity modifier to improve the film thickness and/orantiwear performance of such a lubricating composition.

Lubricating oil compositions desirably maintain a relatively stableviscosity over a wide range of temperatures. Viscosity modifiers areoften used to reduce the extent of the decrease in viscosity as thetemperature is raised or to reduce the extent of the increase inviscosity as the temperature is lowered, or both. Thus, a viscositymodifier ameliorates the change of viscosity of an oil containing itwith changes in temperature. The fluidity characteristics of the oil arethereby improved.

Traditional dispersant viscosity modifiers (DVMs) made fromethylene-propylene copolymers that have been grafted with maleicanhydride and reacted with various amines have shown desirableperformance to prevent oil thickening in diesel engines and sludgeformation in gasoline engines. However, these materials tend to providepoor antiwear protection, which is an useful performance feature ofengine lubricants.

There is an ongoing need for a viscosity modifier that can provideviscosity and/or sludge control but which also provide good wearprotection.

REFERENCES

U.S. Pat. No. 3,642,728, issued Feb. 15, 1972, entitled SULFONATEPOLYMERS, by Canter, discloses sulfonated polymers, such as polymerswith low unsaturation formed by the polymerization of ethylene orpropylene, particularly polymers with 0.2-10 mole % remainingunsaturation. Sulfonation can be carried out at an aromatic ring withinthe backbone or pendent therefrom.

U.S. Pat. No. 3,870,841, issued Mar. 11, 1975, entitled FLEXIBLEPOLYMERIC COMPOSITIONS COMPRISING A NORMALLY PLASTIC POLYMER SULFONATEDTO ABOUT 0.2 TO ABOUT 10 MOLE % SULFONATE, by Makowski, et al.,describes flexible polymeric compositions prepared from sulfonatedthermoplastic ionomers by incorporating a plasticizer in the ionomer.

U.S. Pub. No. 20090305923, published Dec. 10, 2009, entitled DISPERSANTVISCOSITY MODIFIERS BASED ON MALEIC ANHYDRIDE-STYRENE COPOLYMERS, byVisger, et al., discloses dispersant viscosity modifiers based on maleicanhydride-styrene copolymers.

U.S. Pub. No. 20130303418, published Nov. 14, 2013, entitled HIGHMOLECULAR WEIGHT POLYMERS AS VISCOSITY MODIFIERS, by FALENDER, et al.,discloses a lubricating composition which comprises a base oil andbetween 10 ppm and 1000 ppm by mass of a viscosity modifier, theviscosity modifier comprising an olefin copolymer. The use of additionalmonomers is anticipated to allow the inventive polymer to have theproperties of dispersants, antioxidants, pour point depressants andother additive chemistry.

U.S. Pub. Nos. 20120178656 and 20120178659, entitled DISPERSANTVISCOSITY MODIFIERS, by Sutton, et al., and Price, et al., disclose agrafted polymer useful as a dispersant viscosity modifier in lubricatingcompositions. The polymer backbone includes an olefin block and a vinylaromatic block. The polymer is grafted with a pendant carbonylcontaining group, which may be substituted to provide ester, imideand/or amide functionality.

BRIEF DESCRIPTION

In accordance with one aspect of the exemplary embodiment, a lubricatingcomposition includes an oil of lubricating viscosity and an oil-solubledispersant viscosity modifier which includes an olefin-based polymerbackbone and at least one pendent functional group. Each of the at leastone pendent functional group is independently attached to theolefin-based polymer backbone by a linking group. The at least onependent functional group includes a sulfonate moiety.

In accordance with another aspect of the exemplary embodiment, a processfor making a lubricating composition includes: (i) providing anolefin-based polymer backbone with one or more acylating linking groups,each independently attached along the polymer backbone; (ii) optionally,reacting each acylating group with a hydroxy alkyl amine, an alkylenepolyamine, a polyol, or a combination thereof, resulting in anolefin-based polymer with one or more linker units each independentlyattached along the polymer backbone; and (iii) reacting each linkinggroup or linker unit with a hydrocarbyl sulfonate compound, resulting ina dispersant viscosity modifier comprising one or more pendenthydrocarbyl sulfonate groups each independently attached to theolefin-based polymer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a Stribeck plot of traction coefficient vs log mean speed(mm/s) for lubricating compositions formed with and without a sulfonateddispersion viscosity modifier; and

FIG. 2 is a plot of Central Film Thickness (nm) vs speed (m/s) forlubricating compositions formed with and without a sulfonated dispersionviscosity modifier.

DETAILED DESCRIPTION

The exemplary embodiment relates to a lubricating composition whichincludes an oil of lubricating viscosity and a sulfonated dispersantviscosity modifier that includes an olefin-based polymer with pendentgroups having sulfonate functionality.

The exemplary sulfonated dispersant viscosity modifier has improvedperformance in engine tests, providing a good viscosity index, good sootdispersion and/or toleration properties, while also providing goodantiwear protection and/or film thickness performance.

The exemplary lubricating composition finds particular application as anengine oil for passenger vehicles and heavy duty diesel vehicles.

The amounts of additives present in the lubricating compositiondisclosed herein are expressed on an oil free basis, i.e., amount ofactives, unless otherwise noted.

The Dispersant Viscosity Modifier

The exemplary sulfonated dispersant viscosity modifier is a materialthat provides viscosity modifier performance in a lubricatingcomposition while also providing dispersant functionality. Thedispersant viscosity modifier may provide additional and or otherbenefits to a lubricating composition.

The exemplary dispersant viscosity modifier is an oil-soluble polymer,which includes a polymer backbone, such as an olefin-based polymer, andone or more pendent hydrocarbyl sulfonate groups each independentlyattached to the olefin-based polymer. The pendent hydrocarbyl sulfonategroups each include a sulfonate moiety, which can be in the form of asulfonate salt or a sulfonic acid group, and a hydrocarbyl group, suchas an alkyl and/or aryl group, which spaces the sulfonate moiety fromthe polymer backbone and connects it thereto

By “oil soluble,” it is meant that the dispersion viscosity modifier issoluble in oil at least to the amounts described herein for desirablefor serving its intended purpose.

Each of the pendent groups is attached to the polymer chain by a linkinggroup that is grafted onto the olefin-based polymer or forms a part ofthe polymer backbone. The linking group thus links the pendent group tothe olefin-based polymer. Each linking group may be derived from adicarboxylic acid, such as maleic anhydride, that can be linked to thependent group directly or indirectly, via a linker unit. In the case ofa linker unit, the linking group may be grafted to the polymer backboneby first reacting a dicarboxylic acid, such as maleic anhydride, to thepolymer backbone using a peroxide catalyst to form the linking group andthen attaching the linker unit by esterification, imidation oramidation.

The sulfonated dispersant viscosity modifier can be represented by amolecule of the general formula (I):

P—(X—Y—Z)_(x)  (I),

where P represents the olefin-based polymer, X represents the linkinggroup, Y represents an optional intermediate linker unit, Z representsthe pendent hydrocarbyl sulfonate group, and x is at least 1, such asfrom 1 to 20, or 1 to 10, or 1 to 8, e.g., at least 2. As it will beappreciated, there may be many molecules of Formula (I) in thelubricating composition, so the values of x may be considered numberaverage values over all the molecules present. A ratio by weight oflinking groups X to the polymer backbone P in the dispersant viscositymodifier may be at least 1:100, or at least 2:100, such as at least3:100, and in some embodiments, is up to up to 20:100 or up to 10:100.As will be appreciated, P in Formula (I) may contain a range ofmolecular weights, commonly characterized by a molecular weightdistribution, so the values of x may be considered number average valuesover all the molecules present.

In some embodiments, P is an ethylene-olefin-based copolymer and theviscosity modifier of Formula (I) is represented by Formula (II) or(III):

—[[(CH₂)_(m)—(CHR¹—CH₂)_(n))]_(p-q)—[(CH₂)_(m)—(CR¹(X—Y—Z)—CH₂)_(n)]_(q)]_(k)—  (II)

—[[(CH₂)_(m)—(CHR¹—CH₂)_(n)]_(p)—[X(Y—Z)]_(q)]_(k)—  (III)

where each R¹ represents H or an alkyl group containing from 1 to 8carbon atoms,

m, n, p and q are independently at least 1,

k is at least 1, such as at least 2.

In some embodiments, a ratio of m:n may be from 1 to 6. The ratio of m:nmay be 1.5 to 2.3, or 2.3 to 3.5, or 3.5 to 6. In some embodiments, aratio of the number of hydrocarbyl sulfonate groups q:number ethyleneolefin units p in the molecules of Formulas (II) and (III) (e.g.,averaged over all molecules) is at least 0.01. In some embodiments, theratio of q:p may be at least 0.02, or at least 0.03, or at least 0.1, orat least 0.2 and may be up to 0.9, or up to 0.5.

Formula (II) represents a viscosity modifier in which the linking groupX is grafted onto the polymer backbone P, which can be of the generalform —[(CH₂)_(m)—(CHR¹—CH₂)_(n)]_(p)— prior to grafting. Formula (III)represents a viscosity modifier in which the linking group X is integralwith the polymer backbone P.

As will be appreciated, fewer than all of the linking groups X may belinked to a hydrocarbyl sulfonate group Z, although in one embodiment, amajority (at least 50%), or substantially all (at least 80%, or at least90%, or at least 95%), or all of the linking groups X are linked to arespective hydrocarbyl sulfonate group Z.

The hydrocarbyl sulfonate group Z may be derived from a hydrocarbylsulfonate compound, such as an alkyl or aryl sulfonic acid, sourcethereof, or salt thereof. The hydrocarbyl sulfonate group Z can berepresented by the general formula —[R²(SO₃)⁻]_(r)M^(r+), where R²represents a hydrocarbyl group, and M^(r+) represents a cation, where ris at least 1. The sulfonate moiety in the hydrocarbyl sulfonate group Zcan thus be represented by —[(SO₃)⁻]_(r)M^(r+). M^(r+) may be selectedfrom H⁺ (the acid form) and other cations, such as metal cations andaliphatic amine cations of the form —(NR³R⁴R⁵), where R³, R⁴, and R⁵ areindependently selected from H and C₁ to C₃₀ hydrocarbyl groups, such asaliphatic groups, e.g., C₁ to C₃₀ alkyl groups. In one embodiment, atleast one or at least two of R³, R⁴, and R⁵ is an alkyl group and inanother embodiment, each of R³, R⁴, and R⁵ is an alkyl group. In someembodiments, the alkyl groups have at least 2, or at least 3, or up to20, or up to 10 carbon atoms. Example metal cations include alkalimetals, such as K⁺, Na⁺, Mg⁺², Ca²⁺, and mixture thereof. In someembodiments, the dispersant viscosity modifier is metal free, and thecation is a non-metal cation. To avoid cross-linking, the cation issuitably a monovalent cation, i.e., r is 1, although minor amounts ofmultivalent cations may be present. Where a base is to be present in thelubricating composition, the sulfonate moiety may be selected fromoil-soluble salts to avoid formation of oil-insoluble or sparinglysoluble salts through reaction with the base.

The term “hydrocarbyl group” is used herein in its ordinary sense, whichis well-known to those skilled in the art. Specifically, it refers to agroup having a carbon atom directly attached to the remainder of themolecule and having predominantly hydrocarbon character. Examples ofhydrocarbyl groups include:

(i) hydrocarbon substituents, that is, aliphatic (e.g., alkyl oralkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, andaromatic-, aliphatic-, and alicyclic-substituted aromatic substituents,as well as cyclic substituents wherein the ring is completed throughanother portion of the molecule (e.g., two substituents together form aring);

(ii) substituted hydrocarbon substituents, that is, substituentscontaining non-hydrocarbon groups which, in the context of thisinvention, do not alter the predominantly hydrocarbon nature of thesubstituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy,mercapto, alkylmercapto, nitro, nitroso, and sulfoxy);

(iii) hetero substituents, that is, substituents which, while having apredominantly hydrocarbon character, in the context of this invention,contain other than carbon in a ring or chain otherwise composed ofcarbon atoms.

Heteroatoms include sulfur, oxygen, nitrogen, and encompass substituentssuch as pyridyl, furyl, thienyl, and imidazolyl. In general, no morethan two, and in some embodiments, no more than one non-hydrocarbonsubstituent is present for every ten carbon atoms in the hydrocarbylgroup. In one embodiment, there are no non-hydrocarbon substituents inthe hydrocarbyl group.

In one embodiment, the hydrocarbyl group R² of the hydrocarbyl sulfonategroup Z is or includes an alkyl group, such as a C₃ to C₂₄ alkyl groupor C₃-C₂₀ alkyl group, which spaces the sulfonate moiety from thepolymer backbone by at least three carbon atoms, which may be in theform of a chain and/or ring. In another embodiment, the hydrocarbylgroup R² is or includes an aryl group, such as a C₆ to C₂₀ aryl groupwhich spaces the sulfonate moiety from the polymer backbone by anaromatic ring. One or more of the carbons in the hydrocarbyl group R²may be substituted with heteroatoms.

In some embodiments, the sulfonated dispersant viscosity modifierincludes from 1 to 50 of the described hydrocarbyl sulfonate groups Z,or from 1 to 30, or from 1 to 20, or 1 to 10, or from 1 to 6, or 1 to 4,per molecule of the dispersant viscosity modifier, on average. In someembodiments, the sulfonated dispersant viscosity modifier includes 1, 2,3, 4, 5 or 6 hydrocarbyl sulfonate groups Z, on average.

The exemplary linking groups X are acylating groups, each independentlyattached along the polymer's backbone. The linking group X may bederived from an ethylenically unsaturated carboxylic acid monomer, suchas a dicarboxylic acid, or functional equivalent thereof, or a polyol.In one embodiment, the intermediate linker unit Y may be derived from ahydroxy alkyl amine, an alkylene polyamine, or a combination thereof. Insome embodiments, the linking group X is derived from maleic anhydrideand the linker unit Y is derived from a hydroxy alkyl amine. In someembodiments, the unsaturated carboxylic reactant is grafted on to theolefin-based polymer backbone and the hydroxy alkyl amine and/oralkylene polyamine is reacted with the unsaturated carboxylic reactantgroup containing olefin-based polymer backbone. In other embodiments,the unsaturated carboxylic reactant is present in the olefin-basedpolymer backbone and the hydroxy alkyl amine and/or alkylene polyamineis reacted with the unsaturated carboxylic reactant group containingolefin-based polymer backbone.

In another embodiment, the hydrocarbyl sulfonate compound includes anamine or —OH functional group which can serve as an intermediate linkerunit Y. In this embodiment, the unsaturated carboxylic reactant may begrafted on to the olefin-based polymer backbone and the amine/alcoholfunctional group of the hydrocarbyl sulfonate compound is reacted withthe unsaturated carboxylic reactant group containing olefin-basedpolymer backbone. Where the unsaturated carboxylic reactant is presentin the olefin-based polymer backbone the amine/alcohol functional groupof the hydrocarbyl sulfonate compound is reacted with the unsaturatedcarboxylic reactant group containing olefin-based polymer backbone.

The polymer backbone P employed in the sulfonated dispersant viscositymodifier is not particularly limited, provided that it can be modifiedwith a carboxylic acid functionality or a reactive equivalent of thecarboxylic acid functionality (e.g., anhydride or ester) that serves asthe linking group described above.

Suitable olefin-based polymer backbones P include ethylene, propylene,and butylene polymers, copolymers thereof, copolymers thereof furthercontaining a non-conjugated diene, and isobutylene/conjugated dienecopolymers, each of which can be subsequently supplied with, e.g.grafted with, carboxylic functionality to serve as the linking group orhave carboxylic functionality in the backbone itself (such as anethylene-co-propylene-co-maleimide copolymer). In some embodiments, thepolymer backbone P is a copolymer of ethylene and an α-olefin, such aspropylene and/or butylene. Example ethylene-olefin-based polymersinclude ethylene propylene copolymers. In some embodiments, theolefin-based polymer is a copolymer where ethylene makes up at least 10%of the monomer used to prepare the copolymer on a molar basis, or atleast 20 mole %, or at least 50 mole %.

Ethylene-propylene or higher alpha monoolefin copolymers may consist of15 to 80 mole % ethylene and 20 to 85 mole % propylene or highermonoolefin. In some embodiments, the mole ratio is 30 to 80 mole %ethylene and 20 to 70 mole % of at least one C₃ to C₁₀ alpha monoolefin,for example, 50 to 80 mole % ethylene and 20 to 50 mole % propylene.Terpolymer variations of the foregoing polymers may contain up to 15mole %, or up to 10 mole % of a non-conjugated diene or triene.

In these embodiments, the polymer backbone (e.g., the ethylene copolymeror terpolymer), can be an oil-soluble, substantially linear, rubberymaterial. Also, in certain embodiments, the polymer can be in formsother than substantially linear, that is, it can be a branched polymeror a star polymer. The polymer can also be a random copolymer or a blockcopolymer, including di-blocks and higher blocks, including taperedblocks and a variety of other structures.

The polymer backbone (olefin-based polymer) may have a number averagemolecular weight Mn (measured by gel permeation chromatography, using apolystyrene standard), which can be up to 150,000 or higher, e.g., atleast 1,000 or at least 3,000 or at least 5,000, such as up to 150,000or up to 120,000, or up to 100,000, or up to 50,000, or up to 15,000,e.g., about 3,000 to about 15,000. The sulfonated dispersant viscositymodifier may have a number average molecular weight Mn (by gelpermeation chromatography, polystyrene standard), which can be up to150,000 or higher, e.g., at least 2,000 or at least 3,000 or at least5,000, such as up to 150,000 or up to 120,000, or up to 100,000, or upto 50,000, or up to 18,000, e.g., about 4,000 to about 16,000.

The term “polymer” is used generically to encompass homopolymers, i.e.,polymers of a single monomer, as well as copolymers, terpolymers and/orinterpolymers. These materials may contain minor amounts of otherolefinic monomers so long as their basic characteristics are notmaterially changed.

In one embodiment, the exemplary sulfonated dispersant viscositymodifier is formed by reacting a carboxylic acid-modified polymerbackbone with a hydroxy alkyl amine and/or alkylene polyamine and/orpolyol and a hydrocarbyl sulfonate compound. In another embodiment, theexemplary dispersant viscosity modifier may be formed by reacting acarboxylic acid-modified polymer backbone with an amino-substitutedhydrocarbyl sulfonate compound. Where a sulfonic acid is formed, theacid may be converted to its salt through reaction with a suitable base.

The unsaturated carboxylic acid monomer used to form the linking group Xmay be derived from maleic acid and/or anhydride. As noted above, thisportion of the linking group may be incorporated and/or attached to thepolymer backbone during the polymerization of the polymer backbone, forexample, by mixing a monomer containing the linking group in with theother monomers used to prepare the polymer backbone. In otherembodiments, this part of the linking group may be added by grafting thegroup onto an already prepared polymer backbone.

As noted above, in some embodiments the unsaturated carboxylic acid usedto form the linking group is contained within a monomer copolymerizedwithin the polymer backbone chain. In other embodiments, the unsaturatedcarboxylic reactant may be present as a pendent group attached by, forexample, a grafting process.

Examples of suitable carboxylic-acid containing polymers, which arerepresentative of the polymer backbone described above with carboxylicreactant portion of the liking group attached, include maleicanhydride-ethylene-propylene copolymers, maleic anhydride-styrenecopolymers, including partially esterified versions thereof, andcopolymers thereof. Nitrogen-containing esterified carboxyl-containinginterpolymers prepared from maleic anhydride and styrene-containingpolymers are described in U.S. Pat. No. 6,544,935 to Vargo et al. Otherpolymer backbones which are used for preparing dispersants may also beused. For example, polymers derived from isobutylene and isoprene aredescribed in U.S. Pub. No. 20040034175 to Kolp. Other suitable polymerbackbones include substantially hydrogenated copolymers of vinylaromatic materials such as styrene and unsaturated hydrocarbons such asconjugated dienes, e.g., butadiene or isoprene. In substantiallyhydrogenated polymers of this type, the olefinic unsaturation istypically substantially completely hydrogenated by known methods, butthe aromatic unsaturation may remain. Such polymers can include randomcopolymers, block copolymers, or star copolymers. Yet other suitablebackbone polymers include styrene-ethylene-alpha olefin polymers, asdescribed in PCT publication WO 2001/030947, and polyacrylates orpolymethacrylates, generically called poly(meth)acrylates. In the caseof such poly(meth)acrylates, the (meth)acrylate monomers within thepolymer chain itself may serve as the carboxylic acid functionality orreactive equivalent thereof which is used to react with the aminefunctionality which provides the linker unit Y. Alternatively,additional acid functionality may be copolymerized into the(meth)acrylate chain or even grafted onto it, particularly in the caseof acrylate polymers.

In certain embodiments, the polymer backbone may be prepared fromethylene and propylene or it may be prepared from ethylene and a higherolefin within the range of (C₃ to C₁₀) alpha-monoolefins, which may thenin either case be grafted with a suitable carboxylic acid-containingmonomer, to serve as the linking group X.

More complex polymer backbones, often designated as interpolymers, mayalso be included. Such materials are generally used to prepare aninterpolymer backbone is a polyene monomer selected from conjugated ornon-conjugated dienes and trienes. The non-conjugated diene component isone having from about 5 to about 14 carbon atoms. In one embodiment, thediene monomer is characterized by the presence of a vinyl group in itsstructure and can include cyclic and bicyclo compounds. Representativedienes include 1,4-hexadiene, 1,4-cyclohexadiene, dicyclopentadiene,5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 1,5-heptadiene, and1,6-octadiene. A mixture of more than one diene can be used in thepreparation of the interpolymer.

The ethylenically unsaturated carboxylic acid monomer may be graftedonto the polymer backbone in a number of ways, such that a resultingpolymer intermediate with linking groups X is characterized by havingcarboxylic acid acylating functions within its structure. Such materialswhich are attached to the polymer typically contain at least oneethylenic bond (prior to reaction) and at least one, or at least two,carboxylic acid (or its anhydride) groups or a polar group which isconvertible into the carboxyl groups by oxidation or hydrolysis. Maleicanhydride or an alkyl-substituted derivative thereof (e.g., methylmaleic anhydride or ethyl maleic anhydride) is suitable for forming thelinking groups. It grafts onto the ethylene copolymer or terpolymer togive two carboxylic acid functionalities. Examples of additionalunsaturated carboxylic materials include chlormaleic anhydride, itaconicanhydride, and the corresponding dicarboxylic acids, such as maleicacid, fumaric acid, acrylic acid, cinnamic acid, and their esters.

Example intermediate polymers of this type are available from Mitsuiunder the tradename Lucant™, such as Lucant™A-5320H polymer. LucantA-5320H is an amorphous copolymer of ethylene and propylene (GPCM_(n)=7700) that is randomly grafted with maleic anhydride (in thepresence of a free radical peroxide initiator in a high shear mixer) toa level of about 3.5 weight % maleic anhydride. The final product hasmolecular weight (GPC polystyrene standards) M_(n)=8810 and M_(w)=17200and a Total Acid Number of 40 to 45 mg KOH/g.

The polymer intermediate may then be reacted with the hydroxy alkylamine, alkylene polyamine, or polyol to provide the intermediate polymerwith linker units Y. In other embodiments, the polymer intermediate isreacted directly with an amine-substituted hydrocarbyl sulfonatecompound or other substituted hydrocarbyl sulfonate compound capable ofreaction with the intermediate polymer.

Hydroxy alkyl amines and/or alkylene polyamines suitable for forminglinker units Y are not overly limited. In some embodiments, they may berepresented by the general formula:

R⁶R⁷N—R⁸—OH or R⁶R⁷N—R⁸—NR⁶R⁷

where each R⁶ and R⁷ is independently hydrogen or a hydrocarbyl groupcontaining from 1 to 6 carbon atoms and each R⁸ is independently analkylene group containing from 1 to 10 carbon atoms.

Suitable hydroxy alkyl amines include amines having at least one aminegroup and at least one hydroxyl group, where the amine group is aprimary, secondary, or tertiary amine group. The hydroxy alkyl aminesmay have 2 to 30 carbon atoms. Example hydroxy alkyl amines may includemono-, di- and tri-alkoxylates of ammonia such as mono- and di- andtri-ethanolamine, hydroxy-containing monoamines such as a diethoxylatedC₁₆ to C₁₈ tallowamine, and hydroxy-containing polyamines such as2-(2-aminoethylamino)ethanol. In some embodiments the hydroxy alkylamine includes 3-hydroxypropyl amine.

Suitable polyamines for forming linker units Y may have from 2 to 30carbon atoms. Example polyamines include alkylenediamines, N-alkylalkylenediamines, and polyalkylenepolyamines. Useful polyamines includeethylenediamine, 1,2-diaminopropane, N-methylethylenediamine,N-tallow(C₁₆-C₁₈)-1,3-propylenediamine, N-oleyl-1,3-propylenediamine,polyethylenepolyamines such as diethylenetriamine andtriethylenetetramine and tetraethylenepentamine andpolyethylenepolyamine bottoms.

Suitable polyols for forming linker units Y are not overly limited. Insome embodiments, they may be represented by the general formula:

HO—R⁹—OH

where R⁹ is hydrocarbyl group, and in some embodiments an alkylenegroup, containing from 1 to 10 carbon atoms. In some embodiments, thesulfonated dispersant viscosity modifier is prepared using an alkylenediol, an amino-polyol, or combinations thereof. Examples of suitablediols include butanediol, hexanediol,2-amino-2-hydroxymethyl-propane-1,3-diol, and combinations thereof.

As noted above, the reaction product of the olefin-based polymerbackbone containing the unsaturated carboxylic reactant and the hydroxyalkyl amine and/or alkylene polyamine and/or polyol may then be reactedwith the hydrocarbyl sulfonate compound to provide the dispersantviscosity modifier.

In some embodiments, the sulfonated dispersant viscosity modifier is thereaction product of (i) an olefin-based polymer, for example an ethylenepropylene copolymer, that has been functionalized with a unsaturatedcarboxylic reactant, for example, by using maleic anhydride, and (ii) ahydroxy alkyl amine and/or an alkylene polyamine, for example, a hydroxyalkyl amine such as 3-hydroxypropylamine. The resulting intermediate canthen be reacted with a hydrocarbyl sulfonate compound (which maythereafter be converted to a salt) to provide a dispersant viscositymodifier.

In other embodiments, the sulfonated dispersant viscosity modifier isthe reaction product of (i) an olefin-based polymer, for example anethylene propylene copolymer, that has been functionalized with aunsaturated carboxylic reactant, for example, by using maleic anhydride,and (ii) an amine-substituted hydrocarbyl sulfonate compound (which maythereafter be converted to a salt by reaction with a base) to provide adispersant viscosity modifier.

Suitable hydrocarbyl sulfonate compounds for forming the pendentfunctional groups are of the general form:

B-A-SO₃M

where A represents a hydrocarbyl group or a substituted hydrocarbylgroup, M is a cation as described above, and B represents a functionalgroup capable of reacting with the linker unit Y, or capable ofundergoing direct acylation with the linking group X. B can be NH₂(giving an amine-substituted hydrocarbyl sulfonate compound, H₂N-A-SO₃M)or OH. The hydrocarbyl sulfonate compounds can also be in the form of aring capable of reaction with water to form B-A-SO₃H. The hydrocarbylgroup A may be at least 3 carbons in length and may be selected fromC₃-C₂₀ alkyl groups and C₆-C₂₄ aryl or alkylaryl groups, as discussedfor R² above. M may represent a monovalent cation. Where group B iscapable of acylation by the linking group, the linker unit can beomitted, although it may still be useful for chain extension to spacethe lipophilic sulfonate moiety further from the backbone.

Example alkyl hydrocarbyl sulfonate compounds suitable for forming thependent functional groups include aliphatic sulfonic acids representedby formula (IV):

where c is from 1-10,

B is NH₂ or OH, and

R¹¹ and R¹² are independently H or a C₁ to C₃₀ alkyl group.

Examples of formula (V) include 3-hydroxypropane-1-sulfonic acid:

and

3-amino-1-propane sulfonic acid:

Examples of substituted alkyl sulfonate compounds include homocysteicacid:

Example cyclic sulfonic acids, known as sultones which have thesulfonyl-oxy group —OSO₂— in a ring, can be represented by formula (V):

where d is from 1-10, such as 1 or 2, and

R¹³, R¹⁴, and R¹⁵ are independently H or a C₁ to C₃₀ alkyl group.

Useful sultones include, for example, 1,3-propanesultone (d=1, R¹³, R¹⁴,R¹⁵=H),

1,4-butanesultone (d=2, R¹³, R¹⁴, R¹⁵=H):

and C₁-C₁₀ alkyl-substituted derivatives thereof, such as those with CH₃substitutions at one or more of the R¹³, R¹⁴, and R¹⁵ positions.Sultones can react in water to form the corresponding hydroxyalkylsulfonic acid. Such hydrocarbyl sulfonate compounds are capable ofreaction with OH groups of the linker units Y of the intermediatepolymer. For example, 1,3-propanesultone yields products with a terminal—CH₂—CH₂—CH₂—SO₃H group and 1,4-butanesultone yields products with aterminal —CH₂—CH—CH₂—CH₂—SO₃H group, where the terminal H cansubsequently be converted to another cation M as described above.

Examples of aryl sulfonate compounds include those of general formulas(VI), (VII), (VIII), (IX), and (X):

where R¹⁶, R¹⁷, R¹⁸, and R¹⁹, are independently selected from H, OH,NH₂, C₁-C₃₀ (or C₁-C₁₀) alkyl groups, and alkoxy groups,

R²⁰ is H or a C₁-C₃₀ (or C₁-C₁₀) alkyl group, and

e is at least 1, such as 1-20 or 1-10,

In exemplary embodiments, the NH₂ group may be positioned ortho, meta,or para to the sulfonic acid group. Additional substituents, e.g., justone, can be positioned on the ring in the locations not occupied by theamine or sulfonic acid. In some embodiments the substituent is a methylgroup, but can also be a hydroxy (—OH) group, an alkoxy (—OR) group, anitroxy (—NO₂) group, or another amine.

Examples of aryl sulfonate compounds according to formula (VI) includep-aminobenzenesulfonic acid (sulfanilic acid):

As illustrated in Formulas (VII), (VIII), (IX), and (X) the aryl groupcan be based on naphthalene. In such embodiments, the sulfonic acid mayoccupy either the 1 or 2 position on the ring and the amine may beeither on the same ring or on the adjoining ring. Substituents can bethe same noted for single ring aryl groups and may occupy any sites notoccupied by the amine or sulfonic acid.

Examples of aryl sulfonate compounds according to formula (IX) include7-amino-1,3-naphthene disulfonic acid:

Examples of aryl sulfonate compounds according to formula (X) include8-(2-aminoethylamino)-1-naphthene sulfonic acid:

and substituted derivatives thereof.

Where the resulting molecule includes a sulfonate moiety which is asulfonic acid, it can be subsequently converted to the salt by reactionwith a suitable base. Exemplary bases for conversion of the acid form ofthe sulfonate moiety to the respective sulfonate salt include metalhydroxides, such as NaOH, KOH, and Ca(OH)₂, and alkyl amines, such asdi- or tri-alkyl amines of the general form NR³R⁴R⁵, where R³, R⁴, andR⁵ are as described above. The alkyl amine may have alkyl groups having1 to 30, or 2 to 20, or 3 to 10 carbon atoms. Examples of dialkyl aminesinclude dimethylamine, diethylamine, dipropylamine, dibutylamine,dipentylamine, dihexylamine, dl-(2-ethylhexyl)amine, di-decylamine,di-dodecylamine, di-stearylamine, di-oleylamine, di-eicosylamine, andmixtures thereof. Examples of trialkyl amines include trimethylamine,triethylamine, tripropylamine, tributylamine, tripentylamine,trihexylamine, tri-(2-ethylhexyl)amine, tri-decylamine,tri-dodecylamine, tri-stearylamine, tri-oleylamine, tri-eicosylamine,and mixtures thereof.

The reaction can be carried out in a suitable solvent, such as a diluentoil and/or toluene, at a sufficient temperature, such as at least 90° C.or at least 100° C., but below the boiling point of the solvent or thedecomposition temperature of the product. Alternately, the reaction canbe accomplished in the substantial absence of solvent, e.g., in a twinscrew extruder, Banbury mixer, or similar device.

The sulfonated dispersant viscosity modifier may be present in thelubricating composition at a concentration of at least 0.05 weight %,such as at least 0.1 weight %, or at least 0.2 weight %, or at least 0.5weight %. The sulfonated dispersant viscosity modifier may be present inthe lubricating composition at a concentration of up to 10 weight %,such as up to 5 weight %, or up to 3 weight %, or up to 2.3 weight %.

HLB values reported herein are determined by the Griffin Method (seeGriffin, William C. (1949), “Classification of Surface-Active Agents by‘HLB’”, Journal of the Society of Cosmetic Chemists 1 (5): 311-26 andGriffin, William C. (1954), “Calculation of HLB Values of Non-IonicSurfactants”, Journal of the Society of Cosmetic Chemists 5 (4): 249-56

In Griffin's method, HLB=20*Mh/M, where Mh is the molecular mass of thehydrophilic portion of the molecule and M is the molecular mass of thewhole molecule. This method covers a range from 0-20.

The exemplary sulfonated dispersant viscosity modifier may have an HLBvalue according to the Griffin method, of 1-10, or at least 2, or atleast 2.5, or at least 3, and can be up to 9 or up to 8, or up to 7.

For example, a sulfonated dispersant viscosity modifier with an ethylenepropylene backbone having about 240 CH₂/CH/CH₃ groups has an molecularmass of approximately 3525, as determined by vapor phase osmometry(VPO). When reacted with 3.5 wt % maleic anhydride (e.g., forming LucantA-5320H), each polymer backbone chain has, on average, 3.5 sites whichcan be functionalized with the sulfonate moiety. When reacted with3-aminopropanol (as a linker unit), and sulfanilic acid or butanesultone this provides a head group of the form:

(molecular weight 292.3), or

(molecular weight 254.2)

Considering these entire head group portions as the respectivehydrophilic portion, the Mh term is approximately 292.3*3.5=1023 for thealkyl sulfonic acid-based head group. Therefore, theHLB=20*1023/(3525+1023)=4.5 for a dispersant viscosity modifier composedof an ethylenepropylene copolymer with alkyl sulfonic acid pendentgroups.

In a similar fashion, the HLB for the dispersant viscosity modifiercomposed of an ethylenepropylene copolymer with aryl sulfonic acidpendent groups can be computed as 4.0.

For polymer backbones prepared with greater amounts of maleic anhydridegrafted onto them, such as 6.2 groups per chain, the HLB range can be upto about 6.8 or higher for the alkyl sulfonic acid and up to about 6.2for the aryl sulfonic acid dispersion viscosity modifiers.

Under the method described herein, the entire head group is consideredas the hydrophilic portion, even though it contains some hydrocarbonportions.

Oils of Lubricating Viscosity

The exemplary lubricating composition includes an oil of lubricatingviscosity. Suitable oils include both natural and synthetic oils, oilderived from hydrocracking, hydrogenation, and hydrofinishing,unrefined, refined, re-refined oils or mixtures thereof.

Unrefined oils are those obtained directly from a natural or syntheticsource generally without (or with little) further purificationtreatment.

Refined oils are similar to the unrefined oils except they have beenfurther treated in one or more purification steps to improve one or moreproperties. Purification techniques are known in the art and includesolvent extraction, secondary distillation, acid or base extraction,filtration, percolation and the like.

Re-refined oils are also known as reclaimed or reprocessed oils, and areobtained by processes similar to those used to obtain refined oils andoften are additionally processed by techniques directed to removal ofspent additives and oil breakdown products.

Natural oils useful in making the inventive lubricants include animaloils, vegetable oils (e.g., castor oil), mineral lubricating oils suchas liquid petroleum oils and solvent-treated or acid-treated minerallubricating oils of the paraffinic, naphthenic or mixedparaffinic-naphthenic types and oils derived from coal or shale ormixtures thereof.

Synthetic lubricating oils are useful and include hydrocarbon oils suchas polymerized, oligomerized, or interpolymerized olefins (e.g.,polybutylenes, polypropylenes, propyleneisobutylene copolymers);poly(1-hexenes), poly(1-octenes), trimers or oligomers of 1-decene,e.g., poly(1-decenes), such materials being often referred to as polyα-olefins, and mixtures thereof; alkyl-benzenes (e.g., dodecylbenzenes,tetra-decylbenzenes, dinonylbenzenes, di-(2-ethylhexyl)-benzenes);polyphenyls (e.g., biphenyls, terphenyls, alkylated polyphenyls);diphenyl alkanes, alkylated diphenyl alkanes, alkylated diphenyl ethersand alkylated diphenyl sulfides and the derivatives, analogs andhomologs thereof or mixtures thereof.

Other synthetic lubricating oils include polyol esters (such asPriolube®3970), diesters, liquid esters of phosphorus-containing acids(e.g., tricresyl phosphate, trioctyl phosphate, and the diethyl ester ofdecane phosphonic acid), or polymeric tetrahydrofurans. Synthetic oilsmay be produced by Fischer-Tropsch reactions and typically may behydroisomerized Fischer-Tropsch hydrocarbons or waxes. In oneembodiment, oils may be prepared by a Fischer-Tropsch gas-to-liquidsynthetic procedure as well as other gas-to-liquid oils.

The base oil may be selected from any of the base oils in Groups I-V ofthe American Petroleum Institute (API) Base Oil InterchangeabilityGuidelines, namely

Base Oil Category Sulfur (%) Saturates (%) Viscosity Index Group I >0.03and/or <90 80 to 120 Group II ≦0.03 and ≧90 80 to 120 Group III ≦0.03and ≧90 >120 Group IV All polyalphaolefins (PAOs) Group V All others notincluded in Groups I, II, III or IV

Groups I, II and III are mineral oil base stocks. Oils of lubricatingviscosity may also be defined as specified in April 2008 version of“Appendix E-API Base Oil Interchangeability Guidelines for Passenger CarMotor Oils and Diesel Engine Oils”, section 1.3 Sub-heading 1.3. “BaseStock Categories”. In one embodiment, the oil of lubricating viscositymay be an API Group II or Group III oil. In another embodiment, the oilof lubricating viscosity may be an API Group I oil.

The oil of lubricating viscosity may have a kinematic viscosity of lessthan 15 mm²/s (cSt) at 100° C., and in other embodiments 1-12 or 2-10 or3-8 or 4-6 mm²/s. Kinematic viscosity is determined by ASTM D445-14,“Standard Test Method for Kinematic Viscosity of Transparent and OpaqueLiquids (and Calculation of Dynamic Viscosity),” ASTM International,West Conshohocken, Pa., 2003, DOI: 10.1520/D0445-14. The dispersantviscosity modifier may have a kinematic viscosity at 100° C. of at least35 mm²/s, or at least 100 mm²/s, or at least 500 mm²/s.

The amount of the oil of lubricating viscosity present is typically thebalance remaining after subtracting from 100 wt % the sum of the amountof the sulfonated dispersant viscosity modifier and the otherperformance additives. The oil of lubricating viscosity may be presentin the lubricating composition at a concentration of at least 10 wt %,or at least 20 wt %, or at least 40 wt %, or at least 80 wt %, and maybe up to 99 wt %, or up to 95 wt %, or up to 90 wt %.

The lubricating composition may be in the form of a concentrate and/or afully formulated lubricant. If the lubricating composition (comprisingthe additives disclosed herein) is in the form of a concentrate whichmay be combined with additional oil to form, in whole or in part, afinished lubricant), the ratio of the of these additives to the oil oflubricating viscosity and/or to diluent oil include the ranges of 1:99to 99:1 by weight, or 80:20 to 10:90 by weight. If the lubricatingcomposition (comprising the additives disclosed herein) is in the formof a finished lubricant, the ratio of these additives to the oil oflubricating viscosity and/or to diluent oil include the ranges of 1:99.9to 50:50 by weight, or 1:99 to 30:70 by weight.

Additional Performance Additives

The lubricating composition optionally includes one or more additionalperformance additives. These additional performance additives mayinclude one or more metal deactivators, viscosity modifiers, detergents,friction modifiers, antiwear agents, corrosion inhibitors, dispersants,dispersant viscosity modifiers (other than the exemplary compound),extreme pressure agents, antioxidants, foam inhibitors, demulsifiers,pour point depressants, seal swelling agents, antiwear agents, and anycombination or mixture thereof. Typically, fully-formulated lubricatingoil will contain one or more of these performance additives, and often apackage of multiple performance additives.

In one embodiment, the lubricating composition further includes adispersant, an antiwear agent, a friction modifier, a viscositymodifier, an antioxidant, an overbased detergent, or a combinationthereof, where each of the additives listed may be a mixture of two ormore of that type of additive. In one embodiment, the lubricatingcomposition further includes a polyisobutylene succinimide dispersant,an antiwear agent, a friction modifier, a viscosity modifier (typicallyan olefin copolymer such as an ethylene-propylene copolymer), anantioxidant (including phenolic and aminic antioxidants), an overbaseddetergent (including overbased sulfonates and phenates), or acombination thereof, where each of the additives listed may be a mixtureof two or more of that type of additive.

In one embodiment, the lubricating composition further includes anantiwear agent such as a metal dihydrocarbyl dithiophosphate (typicallyzinc dialkyldithiophosphate), wherein the metal dihydrocarbyldithiophosphate contributes at least 100 ppm, or at least 200 ppm, or200 ppm to 1000 ppm, or 300 ppm to 800 ppm, or 400 ppm to 600 ppm ofphosphorus to the lubricating composition. In one embodiment, thelubricating composition is free of or substantially free of zincdialkyldithiophosphate (ZDDP).

In one embodiment, the lubricating composition further includes adispersant. The dispersant may be present at a concentration of 0 wt %to 20 wt %, such as at least 0.01 wt %, or at least 0.1 wt %, or atleast 0.1 wt %, or at least 1 wt %, or up to 20 wt %, or up to 15 wt %,or up to 10 wt %, or up to 6 wt % of the lubricating composition. In oneembodiment, the dispersant may be present in the composition at aconcentration of 0.2 wt % to 2 wt %.

Suitable dispersants for use in the exemplary lubricating compositionsinclude succinimide dispersants. In one embodiment, the dispersant maybe present as a single dispersant. In one embodiment, the dispersant maybe present as a mixture of two or three different dispersants, whereinat least one may be a succinimide dispersant.

The succinimide dispersant may be a derivative of an aliphaticpolyamine, or mixtures thereof. The aliphatic polyamine may be aliphaticpolyamine such as an ethylenepolyamine, a propylenepolyamine, abutylenepolyamine, or mixtures thereof. In one embodiment, the aliphaticpolyamine may be ethylenepolyamine. In one embodiment, the aliphaticpolyamine may be selected from the group consisting of ethylenediamine,diethylenetriamine, triethylenetetramine, tetraethylenepentamine,pentaethylenehexamine, polyamine still bottoms, and mixtures thereof.

The dispersant may be a N-substituted long chain alkenyl succinimide.Examples of N-substituted long chain alkenyl succinimides includepolyisobutylene succinimide. Typically, the polyisobutylene from which apolyisobutylene succinic anhydride is derived has a number averagemolecular weight of 350 to 5000, or 550 to 3000 or 750 to 2500.Succinimide dispersants and their preparation are disclosed, forexample, in U.S. Pat. Nos. 3,172,892, 3,219,666, 3,316,177, 3,340,281,3,351,552, 3,381,022, 3,433,744, 3,444,170, 3,467,668, 3,501,405,3,542,680, 3,576,743, 3,632,511, 4,234,435, Re 26,433, and U.S. Pat.Nos. 6,165,235, 7,238,650, and EP Patent Application 0 355 895 A.

The dispersant may also be post-treated by conventional methods by areaction with any of a variety of agents. Among these are boroncompounds, urea, thiourea, dimercaptothiadiazoles, carbon disulfide,aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinicanhydrides, maleic anhydride, nitriles, epoxides, and phosphoruscompounds.

In one embodiment, the lubricating composition further includes adispersant viscosity modifier other than the sulfonated dispersantviscosity modifier described herein. The additional dispersant viscositymodifier may be present at a concentration of 0 wt % to 5 wt %, such asat least 0.01 wt %, or at least 0.05 wt %, or up to 5 wt %, or up to 4wt %, or up to 2 wt % of the lubricating composition.

Suitable dispersant viscosity modifiers include functionalizedpolyolefins, for example, ethylene-propylene copolymers that have beenfunctionalized with an acylating agent such as maleic anhydride and anamine; polymethacrylates functionalized with an amine, and esterifiedstyrene-maleic anhydride copolymers reacted with an amine. Exemplarydispersant viscosity modifiers are disclosed, for example, inWO2006/015130 and U.S. Pat. Nos. 4,863,623; 6,107,257; 6,107,258; and6,117,825.

In one embodiment, the lubricating composition further includes aphosphorus-containing antiwear agent. The antiwear agent may be presentat a concentration of 0 wt % to 3 wt %, such as at least 0.1 wt %, or atleast 0.5 wt %, or up to 3 wt %, or up to 1.5 wt %, or up to 0.9 wt % ofthe lubricating composition. The phosphorus-containing antiwear agentmay be a zinc dialkyldithiophosphate, or mixture thereof.

In one embodiment, the lubricating composition further includes amolybdenum compound. The molybdenum compound may provide the lubricatingcomposition with 0 to 1000 ppm, or 5 to 1000 ppm, or 10 to 750 ppm 5 ppmto 300 ppm, or 20 ppm to 250 ppm of molybdenum. The molybdenum compoundmay be selected from the group consisting of molybdenumdialkyldithiophosphates, molybdenum dithiocarbamates, amine salts ofmolybdenum compounds, and mixtures thereof.

In one embodiment, the lubricating composition further includes anoverbased detergent. The overbased detergent may be present at 0 wt % to15 wt %, or at least 0.1 wt %, or at least 0.2 wt %, or at least 0.2 wt%, or up to 15 wt %, or up to 10 wt %, or up to 8 wt %, or up to 3 wt %of the lubricating composition. For example, in a heavy duty dieselengine, the detergent may be present at 2 wt % to 3 wt % of thelubricating composition. For a passenger car engine, the detergent maybe present at 0.2 wt % to 1 wt % of the lubricating composition.

The overbased detergent may be selected from the group consisting ofnon-sulfur containing phenates, sulfur containing phenates, sulfonates,salixarates, salicylates, and mixtures thereof.

The overbased detergent may also include “hybrid” detergents formed withmixed surfactant systems including phenate and/or sulfonate components,e.g., phenate/salicylates, sulfonate/phenates, sulfonate/salicylates,sulfonates/phenates/salicylates, as described; for example, in U.S. Pat.Nos. 6,429,178; 6,429,179; 6,153,565; and 6,281,179. Where, for example,a hybrid sulfonate/phenate detergent is employed, the hybrid detergentcan be considered equivalent to amounts of distinct phenate andsulfonate detergents introducing like amounts of phenate and sulfonatesoaps, respectively.

Suitable overbased detergents are sodium salts, calcium salts, magnesiumsalts, or mixtures of the phenates, sulfur containing phenates,sulfonates, salixarates and salicylates. Overbased phenates andsalicylates may have a total base number of 180 to 450 TBN. Overbasedsulfonates may have a total base number of 250 to 600, or 300 to 500. Inone embodiment, the sulfonate detergent may be predominantly a linearalkylbenzene sulfonate detergent having a metal ratio of at least 8, asdescribed, for example, in U.S. Pub. No. 20050065045. The linearalkylbenzene sulfonate detergent may be particularly useful forassisting in improving fuel economy. The linear alkyl group may beattached to the benzene ring anywhere along the linear chain of thealkyl group, but often in the 2, 3, or 4 position of the linear chain,and in some instances, predominantly in the 2 position, resulting in thelinear alkylbenzene sulfonate detergent.

In one embodiment, the lubricating composition includes an antioxidant,or mixture of antioxidants. The antioxidant may be present at 0 wt % to15 wt 5, or 0.1 wt % to 10 wt %, or 0.5 wt % to 5 wt % of thelubricating composition.

Antioxidants include sulfurized olefins, alkylated diarylamines(typically alkylated phenyl naphthyl amines for example thosecommercially available as Irganox® L 06 from CIBA, or alkylateddiphenylamines such as dinonyl diphenylamine, octyl diphenylamine,dioctyl diphenylamine), hindered phenols, molybdenum compounds (such asmolybdenum dithiocarbamates), or mixtures thereof.

The hindered phenol antioxidant often contains a secondary butyl and/ora tertiary butyl group as a steric hindering group. The phenol group maybe further substituted with a hydrocarbyl group (typically linear orbranched alkyl) and/or a bridging group linking to a second aromaticgroup. Examples of suitable hindered phenol antioxidants include2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol,4-ethyl-2,6-di-tert-butylphenol, 4-propyl-2,6-di-tert-butylphenol or4-butyl-2,6-di-tert-butylphenol, or 4-dodecyl-2,6-di-tert-butylphenol.In one embodiment, the hindered phenol antioxidant may be an ester andmay include, e.g., Irganox™ L-135 from Ciba. A more detailed descriptionof suitable ester-containing hindered phenol antioxidant chemistry isfound in U.S. Pat. No. 6,559,105.

In one embodiment, the lubricating composition further includes afriction modifier. The friction modifier may be present at 0 wt % to 6wt %, such as at least 0.05 wt %, or at least 0.1 wt %, or up to 6 wt %,or up to 4 wt %, or up to 2 wt % of the lubricating composition. In oneembodiment, the friction modifier is present in the composition at 0.1to 1.0 wt %. Examples of friction modifiers include long chain fattyacid derivatives of amines, fatty esters, or epoxides; fattyimidazolines such as condensation products of carboxylic acids andpolyalkylene-polyamines; amine salts of alkylphosphoric acids; fattyalkyl tartrates; fatty alkyl tartrimides; or fatty alkyl tartramides. Insome embodiments, the term fatty, as used herein, can mean having a C₈to C₂₂ linear alkyl group.

Friction modifiers may also encompass materials such as sulfurized fattycompounds and olefins, molybdenum dialkyldithiophosphates, molybdenumdithiocarbamates, sunflower oil or monoester of a polyol and analiphatic carboxylic acid.

In one embodiment, the friction modifier may be selected from the groupconsisting of long chain fatty acid derivatives of amines, long chainfatty esters, or long chain fatty epoxides; fatty imidazolines; aminesalts of alkylphosphoric acids; fatty alkyl tartrates; fatty alkyltartrimides; and fatty alkyl tartramides.

In one embodiment, the friction modifier may be a long chain fatty acidester. In another embodiment, the long chain fatty acid ester may be amono-ester or a diester or a mixture thereof, and in another embodimentthe long chain fatty acid ester may be a triglyceride.

Other performance additives such as corrosion inhibitors include thosedescribed in U.S. Pub. No. 20050038319, octyl octanamide, condensationproducts of dodecenyl succinic acid or anhydride and a fatty acid suchas oleic acid with a polyamine. In one embodiment, the corrosioninhibitors include a Synalox® corrosion inhibitor. The Synalox®corrosion inhibitor may be a homopolymer or copolymer of propyleneoxide. Synalox® corrosion inhibitors are described in a productbrochure, Form No. 118-01453-0702 AMS, entitled “SYNALOX Lubricants,High-Performance Polyglycols for Demanding Applications,” published byThe Dow Chemical Company.

Metal deactivators including derivatives of benzotriazoles (such astolyltriazole), dimercaptothiadiazole derivatives, 1,2,4-triazoles,benzimidazoles, 2-alkyldithiobenzimidazoles, or2-alkyldithiobenzothiazoles; foam inhibitors including copolymers ofethyl acrylate and 2-ethylhexylacrylate and copolymers of ethyl acrylateand 2-ethylhexylacrylate and vinyl acetate; demulsifiers includingtrialkyl phosphates, polyethylene glycols, polyethylene oxides,polypropylene oxides and (ethylene oxide-propylene oxide) polymers; pourpoint depressants including esters of maleic anhydride-styrene,polymethacrylates, polyacrylates or polyacrylamides may be useful.

Pour point depressants that may be useful in the compositions of theinvention include polyalphaolefins, esters of maleic anhydride-styrene,poly(meth)acrylates, and polyacrylamides.

In different embodiments, the lubricating composition may have acomposition as described in Table 1:

TABLE 1 Example Lubricating Compositions Embodiments (wt %) Additive A BC Exemplary Sulfonated 0.05 to 10 0.2 to 3  0.5 to 2 DispersantViscosity Modifier Dispersant 0.05 to 12 0.75 to 8  0.5 to 6 OverbasedDetergent 0 or 0.05 to 15 0.1 to 10 0.2 to 8 Antioxidant 0 or 0.05 to 150.1 to 10 0.5 to 5 Antiwear Agent 0 or 0.05 to 15 0.1 to 10 0.3 to 5Friction Modifier 0 or 0.05 to 6 0.05 to 4  0.1 to 2 Viscosity Modifier0 or 0.05 to 10 0.5 to 8    1 to 6 Any Other 0 or 0.05 to 10 0 or 0.05to 8 0 or 0.05 to 6 Performance Additiv Oil of Lubricating Balance to100 Balance to 100 Balance to 100 Viscosity

The sulfonated dispersant viscosity modifier may be present inembodiments (D) at 0.1 to 8 wt %, or (E) 1 to 7 wt %, or (F) 2 to 6 wt%, or (G) 0.1 to 2 wt %, or (H) 0.3 to 1.2 wt % of the lubricatingcomposition, with the amount of dispersant, overbased detergent,antioxidant, antiwear agent, friction modifier, viscosity modifier, anyother performance additive and an oil of lubricating viscosity inamounts shown in the table above for embodiments (A) to (C).

Industrial Applications

In one embodiment, a method of lubricating an internal combustion engineincludes supplying to the internal combustion engine a lubricatingcomposition as disclosed herein. Generally, the lubricating compositionis added to the lubricating system of the internal combustion engine,which then delivers the lubricating composition to the critical parts ofthe engine, during its operation, that require lubrication.

In one embodiment, a use of the dispersant viscosity modifier describedherein to improve film thickness and/or antiwear performance of alubricating composition is provided. These improvements can beconsidered in addition to the dispersancy and viscosity controlperformance expected from a dispersant viscosity modifier.

The lubricating compositions described above may be utilized in aninternal combustion engine. The engine components may have a surface ofsteel or aluminum (typically a surface of steel), and may also be coatedfor example, with a diamond like carbon (DLC) coating. An aluminumsurface may comprise an aluminum alloy that may be a eutectic orhyper-eutectic aluminum alloy (such as those derived from aluminumsilicates, aluminum oxides, or other ceramic materials). The aluminumsurface may be present on a cylinder bore, cylinder block, or pistonring formed of an aluminum alloy or aluminum composite.

The internal combustion engine may or may not have an Exhaust GasRecirculation system. The internal combustion engine may be fitted withan emission control system or a turbocharger. Examples of the emissioncontrol system include diesel particulate filters (DPF), or systemsemploying selective catalytic reduction (SCR).

In one embodiment, the internal combustion engine may be a diesel fueledengine (such as a heavy duty diesel engine), a gasoline fueled engine, anatural gas fueled engine or a mixed gasoline/alcohol fueled engine. Inone embodiment, the internal combustion engine may be a diesel fueledengine and in another embodiment a gasoline fueled engine. In oneembodiment, the internal combustion engine may be a biodiesel fueledengine. The internal combustion engine may be a 2-stroke or 4-strokeengine. Suitable internal combustion engines include marine dieselengines, aviation piston engines, low-load diesel engines, andautomobile and truck engines. In one embodiment the internal combustionengine is a gasoline direct injection (GDI) engine.

The internal combustion engine is distinct from gas turbine. In aninternal combustion engine, individual combustion events which throughthe rod and crankshaft translate from a linear reciprocating force intoa rotational torque. In contrast, in a gas turbine (which may also bereferred to as a jet engine) it is a continuous combustion process thatgenerates a rotational torque continuously without translation and canalso develop thrust at the exhaust outlet. These differences result inthe operation conditions of a gas turbine and internal combustion enginedifferent operating environments and stresses.

The lubricating composition for an internal combustion engine may besuitable for use as an engine lubricant irrespective of the sulfur,phosphorus or sulfated ash (ASTM D874) content. The sulfur content ofthe lubricating composition, which is particularly suited to use as anengine oil lubricant, may be 1 wt % or less, or 0.8 wt % or less, or 0.5wt % or less, or 0.3 wt % or less. In one embodiment, the sulfur contentmay be in the range of 0.001 wt % to 0.5 wt %, or 0.01 wt % to 0.3 wt %.The phosphorus content may be 0.2 wt % or less, or 0.12 wt % or less, or0.1 wt % or less, or 0.085 wt % or less, or 0.08 wt % or less, or even0.06 wt % or less, 0.055 wt % or less, or 0.05 wt % or less. In oneembodiment, the phosphorus content may be 100 ppm to 1000 ppm, or 200ppm to 600 ppm. The total sulfated ash content may be 2 wt % or less, or1.5 wt % or less, or 1.1 wt % or less, or 1 wt % or less, or 0.8 wt % orless, or 0.5 wt % or less, or 0.4 wt % or less. In one embodiment, thesulfated ash content may be 0.05 wt % to 0.9 wt %, or 0.1 wt % to 0.2 wt% or to 0.45 wt %. In one embodiment, the lubricating composition may bean engine oil, wherein the lubricating composition may be characterizedas having at least one of (i) a sulfur content of 0.5 wt % or less, (ii)a phosphorus content of 0.1 wt % or less, (iii) a sulfated ash contentof 1.5 wt % or less, or combinations thereof.

EXAMPLES

The invention will be further illustrated by the following examples,which set forth particularly advantageous embodiments. While theexamples are provided to illustrate the invention, they are not intendedto limit it.

As used herein kinematic viscosity is measured at 100° C. (KV₁₀₀),according to the method of ASTM D445-12, “Standard Test Method forKinematic Viscosity of Transparent and Opaque Liquids (and Calculationof Dynamic Viscosity)”, ASTM International, West Conshohocken, Pa., DOI:10.1520/D0445-12. This test method specifies a procedure for thedetermination of the kinematic viscosity, of liquid petroleum productsby measuring the time for a volume of liquid to flow under gravitythrough a calibrated glass capillary viscometer. It may be noted that 1mm²/s=10⁻⁶ m²/s=1 cSt.

The viscosity index (VI) is determined according to ASTM D2270-10e1,“Standard Practice for Calculating Viscosity Index From KinematicViscosity at 40 and 100° C.,” DOI: 10.1520/D2270-10E01.

The High Temperature/High Shear rate viscosity, HTHS (150° C.), of alubricating composition containing the exemplary dispersant viscositymodifier is determined herein according to the procedure defined in ASTMD4683-10, “Standard Test Method for Measuring Viscosity of New and UsedEngine Oils at High Shear Rate and High Temperature by Tapered BearingSimulator Viscometer at 150° C.,” ASTM International, West Conshohocken,Pa. This test method determines the viscosity of an oil at 150° C. and1.0×10⁶ s⁻¹ using a viscometer having a slightly tapered rotor andstator called the Tapered Bearing Simulator (TBS) Viscometer. Unlessotherwise noted, HTHS values are determined by this method and arereported in centipoise (cP). 1 centipoise=1 mPa-s. (Other suitablemethods to measure HTHS viscosity are ASTM D4741, D5481 or CEC L-36-90but are not used herein unless specifically noted).

Low temperature flow to an engine oil pump or oil distribution system issimulated by measuring engine starting viscosity in centipoise accordingto ASTM D5293-14, “Standard Test Method for Apparent Viscosity of EngineOils and Base Stocks Between −5° C. and −35° C. Using Cold-CrankingSimulator,” DOI: 10.1520/D5293-14.

Example 1: Preparation of a Succinimide Intermediate

A succinimide intermediate is prepared by adding to a 3 L round bottomflask equipped with a mechanical stirrer, thermowell, nitrogen inlet,Dean-Stark trap and Friedrich's condenser, 852.0 grams of a maleatedethylene propylene copolymer, commercially available from Mitusi asLucant™ A-5320H, and 852.0 g of diluent oil. The material is heated to110° C. with stirring and nitrogen purge. 25.8 grams of 3-aminopropanolis added to the mixture, resulting in the formation of a gel. Xylenes(54 g) are added to the flask with continued heating resulting in thegel eventually melting after about 20 minutes of agitation. The solutionis then warmed to 175° C. and agitated for 4.0 hours. The solution iscooled to 165° C. and held an additional 1.5 hours at this temperature.The resulting polymer is stripped of solvents under deep vacuum at 165°C. for 40 minutes. 1712.0 grams of the succinimide intermediate,appearing as a viscous yellow liquid, is recovered.

Example 2: Preparation of a Maleated Ethylene Propylene Alkyl SulfonicAcid Dispersant Viscosity Modifier

A dispersant viscosity modifier is prepared by adding to a 2 L roundbottom flask equipped with a mechanical stirrer, thermowell, nitrogeninlet, Dean-Stark trap and Friedrich's condenser, 300.0 grams of thesuccinimide intermediate of Example 1 and 328.2 g of diluent oil. Thesolution is heated to 110° C. with agitation and nitrogen purge. Then,11.1 grams of butanesultone are added, followed by toluene (50 ml). Thesolution is agitated at 125° C. for 2 hours, then the temperatureincreased to 150° C. for 6 hours. Solvent is then removed under deepvacuum at 150° C. for 30 min to yield 625.0 grams of product, appearingas a viscous liquid. The resulting dispersant viscosity modifier isreferred to below as 3.5% MAA alkyl sulfonic acid.

Example 3 Preparation of a Maleated Ethylene Propylene Aryl SulfonateSalt Dispersant Viscosity Modifier

A dispersant viscosity modifier is prepared by adding to a 2 L roundbottom flask equipped with a mechanical stirrer, thermowell, nitrogeninlet, Dean-Stark trap and Friedrich's condenser, 430.0 grams ofmaleated ethylene propylene copolymer (Lucant™ A-5320H) and 486.0 g ofdiluent oil. The solution is heated to 120° C. with agitation andnitrogen purge for 1 hour. 31.7 grams of tributylamine is added to theflask followed by 27.2 grams of sulfanilic acid. The flask is heated to160° C. for 7.5 hours. Additional tributylamine (31.7 g) is added to theflask with agitation at 160° C. for 6.75 hours. Excess tributylamine isremoved under deep vacuum at 160° C. for 3 hours. 546.8 g of diluent oilis added to the flask, providing 1430.3 g of product as a dark viscousliquid. The resulting dispersant viscosity modifier is referred to belowas 3.5% MAA aryl tributylammonium sulfonate.

The product of Example 3 may be washed with aqueous acid to facilitate acation exchange from a trialkylammonium ion to an H⁺ ion, effectivelyconverting the salt to an acid, as described in Example 4.

Example 4: Preparation of a Maleated Ethylene Propylene Aryl SulfonicAcid Dispersant Viscosity Modifier

A dispersant viscosity modifier is prepared by adding to a 5 L roundbottom flask equipped with a mechanical stirrer, thermowell, nitrogeninlet, Dean-Stark trap and Friedrich's condenser, 1372.5 grams of thesuccinimide intermediate of Example 3 and 1372.5 g of toluene. Flaskcontents are heated to 40° C. and stirred until homogenous.

A 1 N solution of H₂SO₄ is prepared and charged (274.5 ml) to the flask.Contents of the flask are stirred for 20 min at 40° C. Flask contentsare transferred to a separatory funnel and the phases allowed toseparate. The aqueous phase is removed and the organic phase is returnedto the flask. A 2 N solution of H₂SO₄ is prepared and charged (137.3 ml)to the flask. Contents of the flask are stirred for 20 min at 40° C.Contents of the flask are transferred to a separatory funnel and thephases allowed to separate. The aqueous phase is removed and the organicphase is returned to the flask. 2 N H₂SO₄ (137.3 ml) is charged a secondtime to the flask. Contents of the flask are stirred for 20 min at 40°C. Contents of the flask are transferred to a separatory funnel and thephases allowed to separate. The aqueous phase is removed and the organicphase is returned to the flask. 2 N H₂SO₄ (137.3 ml) is again charged tothe flask. Contents of the flask are stirred for 20 min at 40° C.Contents of the flask are transferred to a separatory funnel and thephases allowed to separate. The aqueous phase is removed and the organicphase is returned to the flask.

Saturated aqueous NaCl (150 ml) is charged to the flask. Contents of theflask are stirred for 20 min at 40° C. Contents of the flask aretransferred to a separatory funnel and the phases allowed to separate.The aqueous phase is removed and the organic phase is returned to theflask. Saturated aqueous NaCl (150 ml) is again charged to the flask.Contents of the flask are stirred for 20 min at 40° C. Contents of theflask are transferred to a separatory funnel and the phases allowed toseparate. The aqueous phase is removed and the organic phase is returnedto the flask. The contents of the flask are heated to 120° C. resultingin the collection of water and toluene. The temperature is increased to135° C. and held, resulting in the collection of additional toluene. Thetemperature is increased to 0.150° C. and held, resulting in thecollection of additional toluene. Vacuum is applied to ˜250 mmHg (˜33331Pascal) at 150° C., resulting in the collection of toluene. Vacuum isfurther applied to 10-15 mmHg (1333-2000 Pa) at 150° C., resulting inthe collection of additional toluene. Vacuum is released and the productis filtered. The resulting product is a dark viscous oil.

Preparation of Lubricating Compositions

1. Passenger Car Engine Oil Formulation

The dispersant viscosity modifier of Example 2 is prepared at 25 wt %polymer in 75 wt % diluent oil. This is blended into a group III baseoil in amounts by weight to form lubricating compositions, as summarizedin Table 2 below. Comparative Example 5 includes an amine-freedispersant viscosity modifier (a polymethacrylate (84% C12-15methacrylate/16% methyl methacrylate), with a weight average molecularweight of 330,000). Examples 6 and 7 contain the dispersant viscositymodifiers of Examples 2 and 4 respectively as well as some of theamine-free dispersant viscosity modifier used in Example 5.

Each of the blends is designed to have nearly equivalent kinematicviscosities at 100° C. (KV₁₀₀) to allow for direct comparison:

KV₁₀₀ about 8.5 cSt,

VI about 222,

HTHS (150° C.) about 2.6 cP,

D5293 (−35° C.) about 3700 cP.

TABLE 2 Treat Rates (wt % of Lubricating Composition) LubricatingComparative composition Example 5 Example 6 Example 7 Example 2 (3.5% —1.44 (0.36% MAA al

 sulfonic active) acid) Example 4 (3.5% — 1.20% MAA aryl sulfonic (0.36%active) acid) amine-free dispersant 6.01% 5.01% (1.80% 5.01% viscositymodifier (2.16% active) active) (1.80% active) Pour Point Depressant 0.1%  0.1%  0.1% Dispersant-Inhibitor 9.18% 9.18% 9.18% Package BaseOil balance balance balance

indicates data missing or illegible when filed

The data in parenthesis is the amount of actives for each component. Theweight % actives are based on the entire composition. TheDispersant-Inhibitor Package may include some oil. The lubricatingcompositions of Examples 5-7 include about 0.75% zincdialkyldithiophosphate (ZDDP) (which delivers about 0.076% phosphorus tothe lubricating composition).

Friction Properties

Friction properties were determined using a Mini Traction Machine (MTM).The lubricants are evaluated in a commercially-available mini-tractiontester machine. A simulated concentrated contact forms between a steelball and a steel disc (Smooth disk). Traction measurements are made at arolling speed (of the steel ball) of 2.5 m/s and a 20% slide to rollratio. The temperature was 140° C. and load was 72N. FIG. 1 shows theStribeck curve obtained.

Given the parameters of this particular experiment, the performance ofthe 3.5% MAA alkyl sulfonic acid in the finished fluid can be measuredin all three regions of the Stribeck curve. The area of interest is themixed regime, which can be found between the two vertical lines. Themixed regime is indicative of the durability of the friction modifiercharacteristics of the dispersant viscosity modifier, as determined bythe Sequence VID engine test (ASTM D7589), which is heavily weightedtowards the mixed regime.

From the MTM data, the 3.5% MAA alkyl sulfonic acid outperformed thebaseline (Example 5) formulation.

2. Heavy Duty Engine Oil Formulation

For this study, comparative Example 8 includes a conventional dispersantviscosity modifier (32 wt % active polymer, 68 wt % oil). In the blendsof Examples 9 and 10, this replaced with either 3.5% MAA alkyl sulfonicacid (prepared at 25 wt % polymer, 75 wt % oil) or 3.5% MAA aryltributylammonium sulfonate (prepared at 29.7 wt % polymer, 70.3 wt %oil) at a treat rate to obtain the following viscometric parameters:

Kv₁₀₀ about 12.1-11.4 cSt

VI about 145

HTHS (150° C.)≦3.5 cP

D5293 (−25° C.) cold crankabout 5800-6600 cP

The treat rates for each NOCH—S dispersant viscosity modifier in thebase oil are shown in TABLE 3.

TABLE 3 Treat Rates (wt % of Lubricating Composition) LubricatingComparative composition Example 8 Example 9 Example 10 Conventional 2.05wt % dispersant viscosity (0.66 wt % modifier active) Example 2 (3.5%2.80 wt % MAA alkyl sulfonic (0.70 wt % acid) active) Example 4 (3.5%0.60 (0.18 wt MAA aryl sulfonic % active) acid) Viscosity Modifier 3.9wt % 3.9 (0.49 wt % 3.9 (0.49 wt % (0.49 wt % active actives) actives)Pour Point 0.2 0.2 0.2 Depressant Dispersant-Inhibitor 14.85 14.85 14.85Package Base Oil Balance Balance Balance

The weight % actives are also based on the entire composition. Thelubricating compositions of Examples 8-10 include about 1% zincdialkyldithiophosphate (ZDDP) (which delivers about 0.11% phosphorus tothe composition). The compositions include about 1% sulfated ash andhave a TBN of about 8.5.

The film thickness of the blends in TABLE 3, when subjected to boundary,mixed and hydrodynamic lubrication conditions is measured by anelastohydrodynamic (EHD) ball on plate rig. Briefly, a chamber isflooded with one of the blends from TABLE 3. The chamber is equippedwith a ball that rolls on a glass plate and a chromium spacer. Bydigital analysis of the interference pattern of reflected light shinedon the ball in contact with the plate, the film thickness is measured tothe nanometer scale. The experiment is performed at 140° C. over avariety of rolling speeds. Conditions are as follows: 0.5 GPa HertzPressure, 17 N.

FIG. 2 shows the EHD data obtained. It can be seen that the Example 9and 10 NOCH—S DVMs both form a thicker film, as compared to comparativeExample 8.

It is known that some of the materials described above may interact inthe final formulation, so that the components of the final formulationmay be different from those that are initially added. The productsformed thereby, including the products formed upon employing lubricantcomposition of the present invention in its intended use, may not besusceptible of easy description. Nevertheless, all such modificationsand reaction products are included within the scope of the presentinvention; the present invention encompasses lubricant compositionprepared by admixing the components described above.

Each of the documents referred to above is incorporated herein byreference in its entirety, as is the priority document and all relatedapplications, if any, of which this application claims the benefit.Except in the Examples, or where otherwise explicitly indicated, allnumerical quantities in this description specifying amounts ofmaterials, reaction conditions, molecular weights, number of carbonatoms, and the like, are to be understood as modified by the word“about.” Unless otherwise indicated, each chemical or compositionreferred to herein should be interpreted as being a commercial gradematerial which may contain the isomers, by-products, derivatives, andother such materials which are normally understood to be present in thecommercial grade. However, the amount of each chemical component ispresented exclusive of any solvent or diluent oil, which may becustomarily present in the commercial material, unless otherwiseindicated. It is to be understood that the upper and lower amount,range, and ratio limits set forth herein may be independently combined.Similarly, the ranges and amounts for each element of the invention maybe used together with ranges or amounts for any of the other elements.

While the invention has been explained in relation to its preferredembodiments, it is to be understood that various modifications thereofwill become apparent to those skilled in the art upon reading thespecification. Therefore, it is to be understood that the inventiondisclosed herein is intended to cover such modifications as fall withinthe scope of the appended claims.

1. A lubricating composition comprising: an oil of lubricatingviscosity; and at least 0.05 wt. % of an oil-soluble dispersantviscosity modifier comprising an olefin-based polymer backbone and atleast one pendent functional group selected from alkyl and arylsulfonate salts, alkyl and aryl sulfonic acids, and combinationsthereof, the olefin-based polymer backbone comprising anethylene-olefin-based copolymer, each of the at least one pendentfunctional group being independently attached to the olefin-basedpolymer backbone by a linking group, the at least one pendent functionalgroup comprising a sulfonate moiety, wherein the at least one pendentfunctional group is derived from a sulfonated hydrocarbyl compoundselected from the group consisting of:

where c is from 1-10, d is from 1-10, e is at least 1, B is NH₂ or OH,R¹¹, R¹², R¹³ and R¹⁴ are independently H or a C₁ to C₃₀ alkyl group,and R¹⁵, R¹⁶, R¹⁷, and R¹⁸ are independently selected from H, OH, NH₂,alkyl groups, and alkoxy groups.
 2. (canceled)
 3. (canceled)
 4. Thelubricating composition of claim 1, wherein the at least one pendentfunctional group is derived from a cyclic sulfonic acid ester.
 5. Thelubricating composition of claim 1, wherein the at least one pendentfunctional group is derived from a sulfonated hydrocarbyl compound ofthe general form:B-A-SO₃M where A represents a hydrocarbyl group, B represents afunctional group capable of reaction with the linking group or with anintermediate linker unit, and M represents a monovalent cation. 6.(canceled)
 7. The lubricating composition of claim 1, wherein thesulfonated hydrocarbyl compound is selected from the group consisting of3-hydroxypropane-1-sulfonic acid, 3-amino-1-propane sulfonic acid,homocysteic acid, 1,3-propanesultone, 1,4-butanesultone,p-aminobenzenesulfonic acid, 7-amino-1,3-naphthene disulfonic acid,8-(2-aminoethylamino)-1-naphthene sulfonic acid, and mixtures thereof.8. The lubricating composition of claim 1, wherein the sulfonate moietyis spaced from the olefin-based polymer backbone by a C₄-C₂₄ hydrocarbylgroup.
 9. (canceled)
 10. The lubricating composition of claim 1, whereinat least some of the linking groups are derived from an ethylenicallyunsaturated carboxylic acid monomer.
 11. The lubricating composition ofclaim 10, wherein the ethylenically unsaturated carboxylic acid monomeris selected from maleic anhydride, maleic anhydrides, chlormaleicanhydride, itaconic anhydride, and corresponding dicarboxylic acids andesters thereof, alkyl-substituted derivatives thereof, and mixturesthereof.
 12. The lubricating composition of claim 10, wherein thelinking groups are attached to the pendent groups by linker unitsderived from at least one of hydroxyl alkyl amines, alkylene polyamines,and polyols.
 13. The lubricating composition of claim 12, wherein atleast some of the linking groups are derived from maleic anhydride andat least some of the linker units are derived from a hydroxyl alkylamine.
 14. The lubricating composition of claim 1, wherein the sulfonatemoiety comprises a sulfonate salt which includes a cation of the generalform —(NR³R⁴R⁵), where R³, R⁴, and R⁵ are independently selected from Hand C₁ to C₃₀ alkyl groups.
 15. The lubricating composition of claim 1,wherein a ratio by weight of linking groups to the polymer backbone inthe dispersant viscosity modifier is at least 1:100.
 16. (canceled) 17.(canceled)
 18. The lubricating composition of claim 1, wherein thedispersant viscosity modifier comprises at least two of the pendentfunctional groups per molecule of the dispersant viscosity modifier, onaverage.
 19. (canceled)
 20. (canceled)
 21. The lubricating compositionof claim 1, wherein the olefin-based polymer backbone comprises anethylene-olefin-based copolymer.
 22. (canceled)
 23. The lubricatingcomposition of claim 1, wherein the olefin-based polymer backbone has anumber average molecular weight, as measured by gel permeationchromatography, using a polystyrene standard, of greater than at least1000.
 24. (canceled)
 25. The lubricating composition of claim 1, whereinthe oil of lubricating viscosity is present in the composition at aconcentration of at least 10 wt. %.
 26. (canceled)
 27. (canceled) 28.(canceled)
 29. The lubricating composition of claim 1, wherein thecomposition further comprises at least one of a dispersant, a detergent,an overbased detergent, an antioxidant a viscosity modifier, a frictionmodifier, a corrosion inhibitor, a pour point depressant, a seal swellagent, a demulsifier, and an antiwear agent.
 30. (canceled)
 31. Aprocess for making a lubricating composition comprising: (i) providingan olefin-based polymer backbone with one or more acylating linkinggroups, each independently attached along the polymer backbone; (ii)optionally, reacting each acylating group with a hydroxy alkyl amine, analkylene polyamine, a polyol, or a combination thereof, resulting in anolefin-based polymer with one or more linker units each independentlyattached along the polymer backbone; and (iii) reacting each linkinggroup or linker unit with a hydrocarbyl sulfonate compound selected fromsulfonate salts and sulfonic acids, resulting in a dispersant viscositymodifier comprising one or more pendent hydrocarbyl sulfonate groupseach independently attached to the olefin-based polymer.
 32. The processof claim 31, wherein the providing of the olefin-based polymer with oneor more acylating linking groups comprises grafting one or moreunsaturated carboxylic reactants onto an olefin-based polymer backbone.33. The process of claim 31, wherein hydrocarbyl sulfonate compound isselected from sulfonated hydrocarbyl compounds of the general form:B-A-SO₃M where A represents a hydrocarbyl group, B represents afunctional group capable of reaction with the acylating linking groupsor linker units, and M represents a monovalent cation.
 34. A method oflubricating an internal combustion engine comprising supplying thelubricating composition of claim 1 to the internal combustion engine.